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Carolyn I. Rodríguez

7 papers in the library · 65 citations · publishing 2020-2025

Papers

Ketamine’s acute effects on negative brain states are mediated through distinct altered states of consciousness in humans

Nature Communications October 19, 2023 Laura M Hack, Xue Zhang, B. Heifets et al. 20 citations

Ketamine rapidly induces altered states of consciousness, but the neural mechanisms are unclear. In a randomized, placebo-controlled study with nonclinical adults, functional neuroimaging examined brain activity during emotional tasks under placebo, low-dose (0.05 mg/kg), and high-dose (0.5 mg/kg) ketamine. Different dissociative experiences had opposing effects on right anterior insula activity: depersonalization reduced task-evoked activity by 0.39 standard deviations, while dissociative amnesia increased it by 0.32 standard deviations. These findings suggest that specific dissociative states may influence how ketamine affects brain activity, potentially informing treatment responses in depression.

Psychedelics and Psychedelic-Assisted Psychotherapy

FOCUS The Journal of Lifelong Learning in Psychiatry January 1, 2021 Collin Reiff, Elon E. Richman, Charles B. Nemeroff et al. 17 citations

A review of clinical trials on psychedelic drugs for psychiatric disorders found the strongest evidence for MDMA and psilocybin, both designated by the FDA as breakthrough therapies for PTSD and treatment-resistant depression, respectively. Evidence for LSD and ayahuasca is observational but suggests potential therapeutic effects for mood, anxiety, trauma, and substance use disorders, as well as end-of-life care. Of 1,603 articles screened, 14 well-designed trials were identified. The database remains insufficient for FDA approval of any psychedelic for routine clinical use, but continued research is warranted.

Psilocybin: From Psychiatric Pariah to Perceived Panacea

American Journal of Psychiatry January 1, 2025 Adrienne Grzenda, Gregory A. Fonzo, Aaron Wolfgang et al. 14 citations

Current evidence does not support recommending psilocybin combined with psychological support (PST) as a psychiatric treatment. More rigorous clinical trials are needed to confirm its effectiveness in larger and more diverse patient groups, determine appropriate dosing, improve blinding methods, and understand how it works and for whom it works best. Comparing it directly with other proven treatments will clarify its potential future role in treating major psychiatric disorders.

Novel Pharmacologic and Other Somatic Treatment Approaches for Posttraumatic Stress Disorder in Adults: State of the Evidence.

The American journal of psychiatry December 1, 2024 Lauren M. Sippel, Jessica L. Hamblen, Benjamin Kelmendi et al. 11 citations

PTSD is common and can become chronic without treatment. First-line treatments are individual trauma-focused psychotherapies, with antidepressants and non-trauma-focused psychotherapies also evidence-based. Many patients do not fully recover, prompting a search for novel treatments. This review critically evaluates emerging pharmacological and somatic interventions, including medication-assisted psychotherapy (e.g., MDMA), novel monotherapies (e.g., ketamine, cannabidiol), and neuromodulation (e.g., transcranial magnetic stimulation), as well as treatments of increasing interest (hyperbaric oxygen, stellate ganglion block, neurofeedback). Evidence for most novel treatments is preliminary and highly variable, though data for transcranial magnetic stimulation are encouraging.

Acute Ketamine Modulated Functional Brain Coupling and Dissociative and Affective States in Human Subjects: Interim Analyses

bioRxiv Preprint Server September 20, 2021 Laura M. Hack, Katherine G. Warthen, Xue Zhang et al. 2 citations preprint

Ketamine, a drug used for depression and anesthesia, causes dose-dependent increases in dissociation and intoxication, reduces emotional insensitivity, and raises stress as measured by cortisol. It alters brain connectivity, particularly between reward and negative affect circuits and thalamic sub-regions. Increased coupling between the amygdala and anteroventral thalamus correlates with greater dissociation and intoxication, while decreased coupling of anteromedial and posterior parietal thalamus correlates with increased sensory reward responsiveness. Drug-altered connectivity involving the nucleus accumbens and thalamic sub-regions shows negative associations with anxiety. These findings help disentangle the brain states underlying ketamine's acute effects, informing its therapeutic use and abuse risk.

Real-world use of classic and non-classic psychedelics in Hispanic/Latino adults with Obsessive-Compulsive Disorder: International findings from the LATINO Study

Brazilian Journal of Psychiatry January 1, 2025 David S. Mathai, Jill O. Robinson, Kevin Wagner et al. 1 citation

Among 2,639 Hispanic and Latin American adults with obsessive-compulsive disorder (OCD) living across the Americas, 9% reported using psychedelics or related substances for treatment. Most (72%) had received traditional treatments like psychiatric medication or psychotherapy. Psilocybin, LSD, and MDMA were the most used psychedelics. Users were more likely to be male, have received non-ERP therapy, and have a comorbid psychiatric diagnosis. Outcomes for OCD symptoms varied widely by drug and were difficult to predict, but were most favorable for classic serotonergic psychedelics. Real-world evidence suggests Hispanic and Latin American adults are exploring psychedelics as a treatment for OCD, though further research is needed to establish safe and effective use.

Ketamine increases activity of a fronto-striatal projection that regulates compulsive behavior

bioRxiv Preprint Server July 6, 2020 Gwynne L. Davis, Adelaide R. Minerva, Argentina Lario et al. preprint

Ketamine rapidly reduces compulsive grooming in a mouse model of obsessive-compulsive disorder by increasing activity in a specific brain circuit connecting the dorsomedial prefrontal cortex to the dorsomedial striatum. Optogenetically mimicking this increased fronto-striatal activity also rescued compulsive behavior, while inhibiting this circuit in normal mice increased grooming. These findings suggest this neural pathway may underlie ketamine's fast-acting therapeutic effects in OCD.